Gear treatment apparatus

ABSTRACT

A gear treatment apparatus, including a workhead for supporting and rotating a gear and a wheelhead having an abrasive wheel resiliently pressed against the gear.

United States Patent Maytay 1 Oct. 23, 1973 GEAR TREATMENT APPARATUS[76] Inventor: Joseph A. Maytay, 174 Whitney Street, Northboro, Mass.01532 221 Filed: July 9,1971

21 Appl.No.: 161,187

[52] [1.8. CI. 51/89, 51/99, 51/105 R,

FOREIGN PATENTS OR APPLICATIONS 51/287 [51] Int. Cl B24b 5/36 [58] Fieldof Search 51/105 R, 131, 89,

51/287, 99; 15/21 R, 21 D, 21 E [571' A gear treatment apparatus,including a workhead for supporting and rotating a gear and a wheelheadhaving [56] '-References Cited UNITED STATES PATENTS Great Britain 15 21D Primary Examiner-Donald G. Kelly Attorney-Norman S. Blodgett ABSTRACTan abrasive wheel resiliently pressed against the gear.

2,682,065 6/1954 Nelson-ct a1. 15/21 D 4Claims,8Dl'-awing Figures '8 v 9l V I1 3,17

A 24 l g 27 I3 I9 1| I g 13/ g] Sol: 26 I El 1 II I I 28 ZS Shoots-5h. 1

INVENTOR.

ATTORNEY JOSEPH A. MATAY Patented Oct. 23, 1973 Patented Oct. 23, 19733,766,688

S Shoots-Shoot 2 Patented Oct. 23, 1973 3,766,688 r 3 Shoots-Shut 5 FIG.{I Tm i 8 :1

GEAR TREATMENT APPARATUS BACKGROUND OF THE INVENTION In the manufactureof gears, after the involute surfaces have been formed, it is commonpractice to bevel the end edges, i.e., the edges between theintersection of the involute surfaces (flanks) and the radial surfacesof the gear. The type of bevel that is produced is usually determined bythe ultimate use of the gear. Sometimes, the only bevel that isnecessary is one which is sufficient to remove any burrs from themachine elements. In other cases, the bevel must be quite substantial toassist the gear in sliding in the axial direction into engagement withanother gear, as is true in the case of automotive, transmissions. Suchbevels are known by various names usually associated with the type ofbevel and its ultimate use; for instance, these operations are known asdeburring, bullet-nosing, and the like. Deburring may take place, forinstance, by placing the gear in a tumbling barrel with abrasiveelements or by holding it by hand against a rotating steel brush. Whenmore substantial bevels are to be produced on the end of the gear, it isnecessary to file them by hand. In any case, all of the prior artprocesses have suffered from the deficiency that they were handoperations and, therefore, very expensive. Furthermore it has beendifficult to obtain the same degree of beveling from gear to gearbecause of human error. These and other difficulties experienced withthe prior other devices have been obviated in a novel manner by thepresent invention.

It is, therefore, an outstanding object of the invention to provide geartreating apparatus for automatically beveling the edges of a gear.

Another object of this invention is the provision of gear treatingapparatus for providing the same amount and type of bevel from workpieceto workpiece.

A further object of the present invention is the provision of apparatusfor finishing the edges of gears which will permit the reduction of costof the operation be cause of the fact that manual labor is used only insetting up the gear but not in the beveling operation itself.

It is another object of the invention to provide apparatus for bevelinggears, that operates almost entirely by the removal of metal without anysubstantial forging or production of additional burrs. I I

- A still further object of the invention is the provision of apparatusfor beveling gears in which opposite flank edges on the same end of agear-tooth or opposite end edges of the gear may be beveled atthe sametime.

It is a further object of the invention to provide gear treatmentapparatus which may be used alternatively for the beveling of smallgears, for the beveling of gears of very large radius, or for thebeveling of gears which are formed in the intermediate portions ofshafts.

It isa still further object of the present invention to provideapparatus for contouring the edges of all types of gears including spur,bevel, spiral-bevel, spherical, and pinion gears, irrespective of thegeometric shape of the flanks.

SUMMARY OF THE INVENTION In general, the invention consists of a geartreatment apparatus having a base on which is mounted a workhead,including a spindle on which a gear can be mounted for rotation aboutits axis. The wheelhead is also mounted on the base and has a rotatablespindle on which abrasive wheels can be mounted. Means is provided forpressing the spindle resiliently in the direction of the gear so thatthe surface of the abrasive wheel cams its way along the gear edge.

More specifically, the spindle is driven at high speed by a turbine-typepneumatic motor. The workhead is swingably connected to the base toallow it to be used at various angular relationships to the wheelheadThe wheelhead spindle is mounted for swinging action about an axis at aright angle to the spindle axis. The base is provided with two sets ofparallel ways mounted along the side edges of the surface of the baseand a wheelhead is mounted on each of the ways and provided with ascrew-type driving means. A secondary set of ways is mounted at one endof the base between the two previously mentioned sets and the tailstockis mounted on the secondary set of ways.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is aside elevational view ofapparatus embodying the principles of the present invention,

FIG. 2 is an end elevational view of the apparatus,

FIG. 3 is a plan view of the apparatus,

FIG. 4 is a side elevational view of the machine showing it in conditionfor beveling gears mounted on an elongated shaft,

FIG. 5 is an end elevational view of the machine in condition forbeveling a gear of large diameter,

FIG. 6 is a right elevation of the machine showing it when in use in theoperation shown in FIG. 5,

FIG. 7 is a plan view of the wheelhead, and

FIG. 8 is a front elevational view of the wheelhead.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIGS 1, 2,and 3, which best show the general features of the invention, the geartreatment apparatus, indicated generally by the reference numeral 10, isshown as consisting of an elongated rectangular base 11 having an upperhorizontal surface 13 at one end of which is mounted a workhead 1'2.Mounted at one side of the base 11 and extending from the surface 13 isa wheelhead 14 having a spindle 15 on which is mounted an abrasivewheel-- 14'. A similar wheelhead 16 is located at the other side of thebase. At the end of the base opposite the workhead 12 is a control box".I d

The wheelhead 14 is slidably mounted on a way 18, which extends alongone long side of the base and is propelled along that way by amotor-driven screw 19. A similar way 21 and screw 22 is located alongthe other side of the base to support and move the wheelhead 16. Mountedon the surface 13 of the base 11 and parallel to and lying between theways 18 and 21 is a set of ways 23 on which is slidably mounted atailstock 24. In FIG. 1 a typical gear 20 is shown being finished, butit has been omitted from FIGS. 2 and 3 for clarity of presentation. Thewheelhead 12 is shown as mounted on a hinge shaft 25 for movement aboutan axis extending across the base 11 perpendicular to the ways 18 and 21and extending in a horizontal direction. Extending from the workhead isa spindle 27 driven by a direct current electric motor 26. Workhead 12is tiltable above the shaft 25 by means of a gear segment 28 operable byhand with the use of a crank on a pinion 29. As is evident in FIG. 1,the spindle 27 is driven by the motor 27 through a pair of bevel gears31 and 32. Spindle 27 is keyed to the beveled gear 32 and extends fromeach side, terminating on one side in of the workpiece and workhead l2and terminating on the other side in chuck 33.

In FIG. 4 it can be seen that the workhead 12 has been rotated 90 fromthe position shown in FIG. 1, so that the shaft 27 is horizontal and thechuck 33 is aligned with the tailstock 24. It is then possible to mounta pinion gear 34 with the chuck 33 grasping one end of the pinion gearshaft and the tailstock 24 having its freely-rotatable center lying in asuitable center at the other end of the pinion gear shaft.

FIGS. and 6 show the apparatus in use with a gear 35 having a very largediameter. For this purpose, the workhead is turned 90 from its conditionin FIG. 1, so that the spindle 27 is horizontal and a spindle extension27' is used. At the outboard end of this extension, a floor station 36is provided. The stanchion has a broad base 37 which rests on the floorbeside the base 11 and, at its upper end, it carries a cradle 38 whichsupports the outboard end of the spindle extension 27 while allowing itto rotate. The gear 35 is held against a shoulder on the spindleextension by alarge washer and nut 39. Because of the fact that the way18 and the feed screw 19 extend to the extreme end of the base 11, it ispossible to bring the wheelheads 14 and 14 to the area of the gear 35 tobring about the grinding operation.

FIGS. 7 and 8 show the details of the wheelhead 14. A generallyhorizontal arm 41 is vertically adjustable along a verticalpost 42 whichis slidably mounted on the way 18 and movable by means of the feed screw19 (see FIG. 1). At the other end of the arm 41 is provided a hinge pin43 which allows an angular adjustment about a vertical pivot of ablock-44. Means is provided to lock the block 44 in this position ofadjustment relative to the arm 41. The arm 41 can also be locked in itsvertical position along the post 42. Extending horizontally through theblock is a rod 45 having mounted on it for rotation about a horizontalaxis, (which is the axis of the rod) a block 46 having a suitablelocking handle 47. A block 48 is mounted on top of the block 46 and isfixed to a vertical rod 49 which extends downwardly through the block 46and is mounted in bearings therein. In other words, the .block 48 isrotatably mounted on the block 46 and an internal coiled flat spring isfastened at its inner end to the rod 49 and, at its outer end, to theblock 46.

The block which carries the outer end of the coil spring is providedwith a collar 51 having a locating mark, while the rod 49 is providedwith a numbered collar 52 which can be rotated to adjust the tension inthe spring. The spindle 15 carrying the abrasive wheel 16 is rotatablycarried in a turbine-type pneumatic motor 53 which is mounted on theblock 48 and is carried with it. Extending between the block 46 and theblock 48 is a linear actuator, such as a pneumatic cylinder 54. Suitablepneumatic lines extend from the control box 17 to the motor 53 and thecylinder 54, but these have been omitted from the drawings for thepurpose of clarity of presentation.

The operation of the apparatus will now be readily understood in view ofthe above description. Assuming that a gear 20 is mounted for rotationabout a vertical axis in the manner shown in FIG. 1, the wheelhead 14 isoperated by actuation of the motor rotating the feed screw 19, so thatthe wheehead is advanced along the ways 18 to a position where theabrasive wheel 16 is adjacent the edges of the gear. The angularity ofthe gear and the wheel can be very carefully selected by a combinationof rotating the workhead 12, about its hinge axis 25 by means of thegear segment 28 and actuating the pinion gear 29. The abrasive wheel 16receives angular adjustment relative to the gear teeth and the gear axisby moving the block 44 relative to the arm 41. By proper selection ofthese angular adjustments, it is possible to produce the operation onthe gear edge either with the periphery of the wheel 16 or with theradial surface of the wheel adjacent the periphery. This would give thetype of operation on the gear edge that is desired in a particularsituation. It is thus possible to obtain a bevel or simply a de-burringoperation, as well as bullet nosing and other desired gear edge forms.By bringing the secondary wheelhead 14 into operation on the other sideof the gear it is possible to have the wheel 16 climb up one flank edgeand fall down the other flank edge of a given tooth, while the abrasivewheel 16 climbs up the second flank edge and falls down the first flankedge. The net result of this is simultaneous grinding of both flankedges of the gear tooth. Furthermore, if desired, the wheel 16 canoperate on the top edge of the gear, while the abrasive wheel 16'operates on the bottom edge, so that a gear can have both ends of itsteeth beveled or rounded at the same time.

In the preferred embodiment, the control box 17 allows for a multiplenumber of rotations of the gear during a given cycle. It may bedesirable, for instance, in some situations, to rotate the gear severaltimes past the wheels to provide the desired beveling. In that case, thecontrol automatically counts the number of rotations before the cylinder54 is actuated to rotate the spindle away from the gear at the end ofthe cycle. In the preferred embodiment, the control box also contains aninterlock to assure that the spindle is maintained in the outwardinoperative position away from the gear until the gear begins rotatingand until the pneumatic motor 53 has come up to speed. Engagement of theabrasive wheel with the gear before the wheel is going at the idealspeed damages both the wheel and'the gear. One ofthe advantages of thepresent invention is that the wheelheads 1'4 and 14" can be movedquickly to the other end of the base out of the way for loading andunloading. To do this it is only necessary to actuate the control buttonon the control box which operates the motors which drive the feed screws19 and 22. It can be understood that a machinist can operate several ofthese machines at the same time, so that he simply loads one machine andleaves it to produce the rounding operation on the gear, while he goeson to the next machine and loads it. In this way, it is not necessaryfor an operator to be present at each machine during the entireoperation. He is able to handle several machines and the cost of laborin rounding a given gear is quite low. In this way, too, the bevel onthe gear edge is the same for all gears, since the parameters have beenset up to give equal pressure, speed, and so on between the wheel andthe gear in each case. Excellent repeatability of gear edge bevel shapeis possible. Because of this it is possible to design transmissions withthe assumption that the leading or sliding of the one gear into anotherwill be the same from transmission to transmission because of thestandardization of the bevel. Because of the unusual construction of theworkhead, it is possible to use a single machine on almost any kind orsize of gear, so that it is not necessary to tie up the capitalinvestment in the machine shop in more machines than can be operated atany given time. It also should be noted that it is possible not only tobevel the entire edge of the end of the gear, but also simply to knockoff the corner edge at the intersection between the flank andthe end ofthe gear; that is to say, the corner. Also, by carefully selecting theangularity between the axis of the abrasive wheel and the axis of thegear, it is possible to bevel one side edge of a tooth without theabrasive wheel striking the other flank of the next adjacent tooth.

The invention having been thus described, what is claimed as new anddesired to secure by Letters Patent is:

I claim:

1. Gear treatment apparatus for treating a gear having a shape,comprising:

a. a base,

b. a workhead mounted on the base and including means to support thegear and rotate it about its axis, the workhead being provided with amotordriven first spindle on which the gear is mounted, and the workheadalso including a hinge located a substantial distance from the spindleaxis and at a right angle thereto,

c. a wheelhead mounted on the base and including a second spindle onwhich is mounted an abrasive wheel and a motor for driving the secondspindle,

d. means associated with the wheelhead to press the wheel toward thegear so that the wheel follows the g shape of the gear as the gearrotates.

2. Gear treatment apparatus as recited in claim 1, wherein the workheadis movable from a first position at which the first spindle is verticalto a second position at which the first spindle is horizontal.

3. Gear treatment apparatus as recited in claim 2, wherein in the secondposition a secondary spindle also extends horizontally, but in theopposite direction, and wherein a tail stock is slidably mounted on thebase for use with the secondary spindle to mount a gear on centers.

4. Gear treatment apparatus, comprising:

a. an elongated rectangular base having a generally flat horizontalupper surface having two long side edges,

b. a workhead mounted at one end of the base and having a motor-drivenspindle on which a gear can be mounted and rotated,

c. a set of ways mounted along each long side edge of the surface of thebase,

d. a wheelhead slidably mounted on each set of ways and including aspindle on which an abrasive wheel is mounted,

e. means associated with each wheelhead to press the wheel resilientlytoward the gear,

f. a secondary set of ways mounted at the other end of the base betweenthe two previously-mentioned sets, and

g. a tail stock mounted on the secondary set.

1. Gear treatment apparatus for treating a gear having a shape,comprising: a. a base, b. a workhead mounted on the base and includingmeans to support the gear and rotate it about its axis, the workheadbeing provided with a motor-driven first spindle on which the gear ismounted, and the workhead also including a hinge located a substantialdistance from the spindle axis and at a right angle thereto, c. awheelhead mounted on the base and including a second spindle on which ismounted an abrasive wheel and a motor for driving the second spindle, d.means associatEd with the wheelhead to press the wheel toward the gearso that the wheel follows the shape of the gear as the gear rotates. 2.Gear treatment apparatus as recited in claim 1, wherein the workhead ismovable from a first position at which the first spindle is vertical toa second position at which the first spindle is horizontal.
 3. Geartreatment apparatus as recited in claim 2, wherein in the secondposition a secondary spindle also extends horizontally, but in theopposite direction, and wherein a tail stock is slidably mounted on thebase for use with the secondary spindle to mount a gear on centers. 4.Gear treatment apparatus, comprising: a. an elongated rectangular basehaving a generally flat horizontal upper surface having two long sideedges, b. a workhead mounted at one end of the base and having amotor-driven spindle on which a gear can be mounted and rotated, c. aset of ways mounted along each long side edge of the surface of thebase, d. a wheelhead slidably mounted on each set of ways and includinga spindle on which an abrasive wheel is mounted, e. means associatedwith each wheelhead to press the wheel resiliently toward the gear, f. asecondary set of ways mounted at the other end of the base between thetwo previously-mentioned sets, and g. a tail stock mounted on thesecondary set.